• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.19 no.7
• /
• pp.1335-1345
• /
• 1994

In this paper, the performance analysis of Inter-Processor Communication Network(IPCN) in a large-capacity digital switching system, TDX-10, is presented. The simulation model of IPCN is developed using discrete event model of SLAM II. The simulation results of maximum buffer length and mean waiting times at each node, and utilization of D-bus are derived. Finally, the maximum call handling capacity of IPCN is obtained by taking link speed into consideration.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.21 no.12
• /
• pp.2261-2269
• /
• 2017

The current LTE network system provides service by locally allocating eNodeB to the EPC(Evolved Packet Core). However, it is not suitable for inter-node communication based on the distributed network environment. In this paper, we propose an integrated system by configuring E-UTRAN and EPC as All-In-One type to enable service in each distributed node. M2M UE is mounted on a each node for wireless In-band backhaul link. The integrated node provides inter-node communication over the wireless in-band backhaul link. If a normal UE moves and an access node changes in the system all entities of LTE integrated into one, it is necessary to change the P-GW which is IP anchor. In order to support the inter-node mobility even if P-GW is changed, We defined UPFE(User Packet Forwarding Extension) scheme and implemented the handover procedure of EPC. Also, we analyze the cell range of the integrated LTE system with the addition of the node and compare the handover delay with the current system.

• Journal of Sensor Science and Technology
• /
• v.22 no.3
• /
• pp.212-218
• /
• 2013

In this paper, we introduce a new method to reduce the inter-channel crosstalk in visible light communication (VLC) systems using the synchronizing pulses transmitted through the power lines. Synchronizing pulses are simultaneously transmitted to multiple VLC transmitters and receivers through the 220V power line. Each VLC transmitter modulates an LED and each VLC receiver demodulates the signal light in the time slot that is allocated with reference to the synchronizing pulses. This method is very simple and effective to prevent the inter-channel crosstalk in VLC systems for sensor networks because every VLC system can easily get the synchronizing pulses from the nearby power line.

• 한국정보통신설비학회:학술대회논문집
• /
• 2008.08a
• /
• pp.525-530
• /
• 2008

There are a few core technologies to enable high-performance $4^{th}$ generation (4G) broadband wireless communication system. A multiple input multiple output (MIMO) provides high-rate transmission through expended channels by multiple array antennas in both sender and receiver side. Also orthogonal frequency division multiplexing (OFDM) is well-known as the most appropriate technique for high data rate transmission such as Mobile WiMAX and WLAN. Efficient decrease of inter-carrier interference (ISI) and inter-carrier interference (ICI) are the reasons for why OFDM is suitable for high-performance transmission, 4G mobile communication. In this paper, we mainly focus on two of objects, combination between MIMO and OFDM, and OFDM channel simulator using Ray-tracing algorithm. The results of this paper can be used implementation of a Wireless Software Platform for 4G Mobile Communication Systems.

• Journal of Convergence for Information Technology
• /
• v.7 no.6
• /
• pp.167-172
• /
• 2017

In this paper, we propose a variable RGB interleaving technique for efficient data transmission in LED based visible light communication system. Visible light communication systems that utilize light as a resource for data transmission are affected by the nature of light and the three primary colors of light. However, the nature of light, such as light reflection, diffraction, and superposition, causes interference of the data to be transmitted, causing burst errors in the data. Such a problem causes the BER performance of the visible light communication system to degrade. To solve these problems, this paper attempts to utilize the variable RGB interleaving technique. Through variable RGB interleaving, data burst errors can be reduced and inter channel interference in a visible light communication system can be reduced. In addition, if the proposed system is applied to meet the QoS that depends on the importance of data or the requirements of the user, it can provide QoS requested by the user and enable efficient data transmission.

• Proceedings of the Korea Inteligent Information System Society Conference
• /
• 2001.01a
• /
• pp.179-185
• /
• 2001

Mobile agents have the unique ability to transport themselves from one system in a network to another. The ability to travel allows mobile agents to move to a system that contains services with which they want to interact and then to take advantage of being in the same host or network as the service. But most of conventional mobile agent systems require that the users or the programmer should give the mobile agent its detail behavioral script for accomplishing the given task. And during its runtime, such mobile agents just behave according to the fixed script given by its user. Therefore it is impossible that conventional mobile agents autonomously build their own plants and execute them in considering their ultimate goals and the dynamic world states. One way to overcome such limitations of conventional mobile agent systems is to develop an intelligent mobile agent system embedding a reactive planner. In this paper, we design both a model of agent mobility and a model of inter-agent communication based upon the representative reactive planning agent architecture called JAM. An then we develop an intelligent mobile agent system with reactive planning capability, IMAS, by implementing additional basic actions for agent moves and inter-agent communication within JAM according to the predefined models. Unlike conventional mobile agents. IMAS agents can be able to adapt their behaviors to the dynamic changes of their environments as well as build their own plans autonomously. Thus IMAS agents can show higher flexibility and robustness than the conventional ones.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.33 no.7A
• /
• pp.693-701
• /
• 2008

In OFDMA (Orthogonal Frequency Division Multiple Access) system that frequency reuse factor is 1, as the same channels in the neighborhood cells creates inter-cell co-channel interference which provides a resource underutilization problem, channel allocation schemes to minimize inter-cell interference have been studied. This paper proposes a new CNIR (Carrier to Noise and Interference Ratio)-based distributed Inter-cell DCA (Dynamic Channel Allocation) algorithm in the OFDMA environment with frequency reuse factor of 1. When a channel allocation is requested, if there is not a free channel in home cell or the available free channels in home cell do not satisfy a required threshold value, the proposed Inter-cell DCA algorithm finds CNIR values of available free channels in the neighborhood cells and then allocates a free channel with maximum CNIR value. Through the simulation results, we find that the proposed scheme decreases both new call block rate and forced termination rate due to new call generation at the same time because it increases channel allocation probability.

• ETRI Journal
• /
• v.36 no.4
• /
• pp.519-527
• /
• 2014

An integrated multi-beam satellite and multi-cell terrestrial system is an attractive means for highly efficient communication due to the fact that the two components (satellite and terrestrial) make the most of each other's resources. In this paper, a terrestrial component reuses a satellite's resources under the control of the satellite's network management system. This allows the resource allocation for the satellite and terrestrial components to be coordinated to optimize spectral efficiency and increase overall system capacity. In such a system, the satellite resources reused in the terrestrial component may bring about severe interference, which is one of the main factors affecting system capacity. Under this consideration, the objective of this paper is to achieve an optimized resource allocation in both components in such a way as to minimize any resulting inter-component interference. The objective of the proposed scheme is to mitigate this inter-component interference by optimizing the total transmission power - the result of which can lead to an increase in capacity. The simulation results in this paper illustrate that the proposed scheme affords a more energy-efficient system to be implemented, compared to a conventional power management scheme, by allocating the bandwidth uniformly regardless of the amount of interference or traffic demand.

• Transactions on Control, Automation and Systems Engineering
• /
• v.1 no.2
• /
• pp.141-146
• /
• 1999

This paper describes the communication method of an auto-startup system. The Auto-Startup system is designed to operate a nuclear power plant automatically during the startup operation . In general , the operations during startup in existing plant have only been manually controlled by the operator. The manual operation caused to the operator mistake. The Auto-Startup system consists of the Distributed Control System(DCS) and G2 (Expert System). Also, Functional Test Facility(FTF) provides the plant's real-data for an Auto-Startup system. So, it is necessary to develop the communication method between these systems. We developed two methods ; one is a network and the other is a hardwire line. To communicate between these systems (DCS-G2 and DCS-FTF) , we developed the communication program. In case of DCS-FTF, we used the TCP/IP and VXI. BUt, in case of DCS-G2 , we , what it called , developed the bridge program using the GSI(G2 Standard Interface). We test to check the function of the important parameter, in time, for analysis of the developed communication method. The results are a good performance when we check the communication time of important parameter. We conclude that Auto-startup system could save heat-up time about at least 5 hours and reduced the change of the reactor operation and trip.

• Journal of Information Technology Services
• /
• v.15 no.1
• /
• pp.113-129
• /
• 2016

Recently, as Information System projects tend to be more complex, the importance of Information System Audit increases. In the same context, the need for the resident IS Audit also increases, which is supposed to deal with the possible risks and urgent issues by providing the appropriate support and timely coordination during IS project. Basically, for the effective IS Audit, the IS audit team members should be able to understand such a business context as work characteristics, business knowledge, goals, and culture of the organization. The audit team members should also be able to share the various knowledge of Information Technology and audit procedure with the owner of the project. Especially, for the resident audit, it is more important to fill the gaps in expertise between project owner and audit team. However, any studies on the need of common knowledge base (knowledge complementarities) in the IS audit have not been done so far. The purpose of this study is to analyze whether the knowledge complementarity based on inter-organizational communication between the project owner and audit team members makes an effect on the fidelity and performance of IS audit. In order to do this, the relationship among inter-organizational communication and knowledge complementarity, the fidelity of IS audit service, and performance of IS audit has been analyzed, using Structural Equation Model. The result shows that all the relationship is significant, which means that knowledge complementarity between the two different interest groups should be an effective factor on the fidelity and performance of IS audit. This result implies that, for better quality of IS Audit service, how to acquire the knowledge complementarity between the project owner and Audit team should be considered seriously as well as systematically in the process of IS Audit.